About Stickleback :
Stickleback is most frequently found fish in the ocean, but can also be found in freshwater lakes. They have evolved special features from the ocean variety. The Gasterosteidae are ancestors of fish as well as of the sticklebacks. They nourish on small crustaceans and fish. The universal name of the family is sticklebacks or tube-snouts, the tube-snouts are at present classified in the associated family of Aulorhynchidae.
Physical features :
Sticklebacks are famous for the presence of strong and visibly isolated spines in the dorsal fin. An extraordinary feature of sticklebacks is that they have no scales on their body, while some species have bony amour plates. They are similar to pipefish and seahorses.
Their highest length is about 5 inches, but only some of them are more than 4 inches long. They grow-up sexually at a length of about 3 inches. All genuses show similar mating behaviors, which is also strange among fish.
The male Sticklebacks build a nest from flora held together by secretion from their kidneys. The males then draw females to the nest that put their eggs inside where the male fish can fertilize them. The male protect the eggs until they hatch.
Three-spined stickleback :
The family of the three-spined stickleback includes Gasterosteus aculeatus, they are widespread in northern temperate climate around the world which includes Europe. They are generally known in the United Kingdom as the tiddler, or sprick. In Ireland, they are usually known as pinkeens due to the rosy color of the male three spined stickleback's throat throughout reproduction season.
Physical features :
The three-spined stickleback has a very lean, with squarish tail fin, like its nine-spined family member, but it is a stouter fish and it is more compressed sidewise. Its most indicative features are the number of dorsal spines,of which there are three and rarely four or five.
This stickleback is very changeable in color. They are usually deep grayish, or olive-green.
They can reach maximum length about 5 inches, but few of them are about 4 inches long. It develops sexually at a length of about 3 inches.
This is typically a shore fish like all the sticklebacks, the great bulk of them live their whole lives in estuarine situations. They are proverbially pugnacious fish, by means of its spines they use as a weapons of offense and guard themselves, from other fishes. It eats erratically on the smaller invertebrates, on fish eggs.
Ninespine stickleback :
Physical Features : The body of the ninespine stickleback is much leaner compared to other members of this family. Its color is light olive or brown and sometime grayish back. The belly is light silvery. They do not have scales on their body nor do they have any bony plates. The ninespine stickleback has a long and thin caudal peduncle and the caudal fin is curved. The standard size of ninespine stickleback is 3.2 inches
The ninespine stickleback is found equally in salty waters and freshwater lakes and rivers. In rivers and streams they are usually found in slower areas where there is plant life.
The diet of the ninespine stickleback includes mostly on marine insects and crustaceans, but they can also eat their own eggs and juvenile of other species of fish.